LAS VEGAS (KLAS) — Zion National Park is warning visitors of a “Danger Advisory” for elevated levels of a toxin produced by cyanobacteria in North Creek, and lower levels have been found in the other park waterways.

A Nov. 4 update from the National Park Service advises visitors to avoid all direct contact with water in North Creek, and continues to warn against drinking water from any stream in the park. Hikers should carry in their own water or filter and disinfect directly from a spring source. There is no known filtration system that is effective at removing cyanotoxins.

In addition to the high toxin levels in North Creek, park officials say cyanobacteria has also been found in the North Fork of the Virgin River and in La Verkin Creek. The North Fork of the Virgin River is under a “Warning Advisory” and La Verkin Creek is under a “Health Watch” as the park continues to monitor levels.

Cyanobacteria forms shelves at the waterline including bulbous growths as seen here. (National Park Service photo)

In July, 2020, cyanobacteria was blamed in the death of a 6-month-old husky puppy named Keanna, which died 20 minutes after coming into contact with a toxic algae bloom in the Virgin River. Since that happened, the park has been monitoring toxin levels in the park’s streams and rivers.

The “Danger Advisory” announced Friday is higher than other warnings issued in June of this year when toxins were found in the North Fork of the Virgin River. There was another warning about toxins announced on Oct. 12.

The park service has not said if there have been sicknesses or hospitalizations linked to contact with the toxins over the past summer.

A scientist samples cyanobacteria in the Virgin River. (File, National Park Service photo)

Children and pets are especially vulnerable to cyanotoxins, according to a park service information page.

“Toxin-producing cyanobacteria of the genera Microcoleus, Tychonema, and Nostoc have been found in the North Fork of the Virgin River, North Creek, and La Verkin Creek. Colonies of cyanobacteria can be yellow, tan, green, brown, or black in color. Toxins detected in Zion include anatoxin-a, nodularin, microcystin, and cylindrospermopsin,” according to the Zion National Park web page.